Differential check-valve for radiators.



W. SHURLEFF.

DIFFERENTIAL CHECK vALvE FOR RDlAToRs.' APPLICATION FILED MAY I8'. 1915.

1,287,1 19. l Patented Dee. 10, w18.

w. "I I I Q N N' I I WIT/VESSES: MII/EN T 0H I' uw.'

A TTU/MIE YS that all. communication ofthe radiator with f 1 lTED -sarna-Es PATENT oFFIcE.. A

WILFILED snUnrLErr, Or iaOLINE, ILLINOIS, A'ssIGNOn TO MOLINE Himnos MOLINE,

f ILLINOIS, A CORPORATION or ILLINOIS.

- 1 f'nIrrnnEN'rInL cnncxfvALvE For.. RADIATORS.

To all whom it may-concern.'

lBe 1t known that I, WILFRED SHURTLEFF,

a citizen of the United States, residing at.

Moline, in the county of Rock Island and State of Illinois, have' invented a new and useful Improvement in Differential Check- Valves for Radiators, of which the following is a specification. 7

In the present practice of steam heat'linstallation, especially that of the two-pipe system, 1t is essential to provide a globe 0r cut-off valve at both the steam inlet side and also at the steam return or .discharge side so the steam pipe lines may be severed w-hen it is vdesired to cool the radiator. Ih certain modiiications of the twpipe system, a valve is provided at the steam inlet side and either a swing-check or ball-check valve at the outlet side of the radiator which valve acts as a check against the return of the steam into the radiator. It has, however,- been found from experience that this method of preventing the reentrance of the steam to the radiator is 'unreliable for the reason that an ordinary check valve will not close suiiiciently tight to serve this purpose and steam can therefore renter the radiator, assuming the inlet valve to have been closed.

Therefore, the object of my invention is Vto provide a fluid operated back-check valve which is to be connected'in the return or steam discharge pipe of a radiator of th two pipe system which back check valve the pipe line vafter the inlet valve in the,`

- tion of a steam heatmg system of the twosteam inlet side has once been cut off.

A further object of my` invention is lto provide a valve in the steam discharge or reto be discharged Into the return or discharge 1pc. P In order that the aforesaid obiects may be accomplished, I provide a valve casmg vconnectible in the return side of a` twopipe steam heating system, at' the top of which casing is clamped a flexible dlaphragm of movement when the valve in the Specication Of' Letters Patent. Patented Decglo, 19:18, i Z Application led lflay' 18, 1915. Serial No. 28,848.

relatively large area which diaphragm in -turn carries a pendent closure valve which coperates with a suitable valve seat formed in the body of the casing.

'In the normal operation of the radiator or when the inlet valve is 4open and the steam pressure is on, the aforesaid valve contained 1n the valve lcasing is raised or opened, this being caused by the pressure of the incominglv steam acting on the underside of the diaphragm from which the valve is pendent, thuskee in the valve raised from its'seat and esta steam.

lShould the steaminlet valve be suddenly closed, a rapid condensation of .the steam within the radiator will result, causing a partial vacuum to form; and since the pressure in the return pipe is now in excess of that in the radiator, the steam in the return pipe will tend to rush into the radiator thus lis ing a through passage for the rangement `of parts, all of which will be hereinafter fully explained and then speciicallypointed out in the appended claim,

reference bein hadfto the accompanying drawmg in wh1ch:- l

Figure l is a diagrammatlcal representapipe type showing my. Invention applied to the steam return pipe.

Fig. 2 is a central vertical section of the 'back-check valve which is the object of my invention, the valve being closed in full lines and open, in dotted lines. v Fig. 3 is a sectional view of theJ lower part' of the valve structure showing the valve raised.

Referring n ow tOFig. 1, 1 is the steam inlet pipe of a heating system of the usual two-pipe type which pipe 1 1s common to a plurality of radiators-2, while 3, indicates the steam, return or discharge pipe which carries' the steam back to the source of supply.

la check valve 5, the detailed operation of.

which will presently be explained.

The valve 5, merges at its upper extremity, with a semi-globular portion 6,

which in turn is flattened horizontally to form a circumferential. flange 7 between which and the corresponding flange of a cover 8, a flexible diaphragm 9 of relatively large area, is ixedly clamped. 10 is a gasket which renders the chamber 1 1, above the diaphragm- 9, steam-tight as well as preventing escape of steam from the interior of the valve 5.

Connected pendently from the diaphragm 9, as at 12, is a stem 13, at the bottom of which is formed a valve whichis adapted to engage a suitably ground seat in the steam discharge port 15 of the valve 5. Arranged vertically in the stem 13, isa bleeder passage 16 which offers communicati an between the chamber 11 and with the discharge pipe 3 and interior of the valve 5, alternately.

Bv providing the diaphragm 9 of relatively large area and a bleeder passage of small diameter through the stem 13 of the valve 14, a diHerential valve with a large area at the top of' same is provided thus affording additional pressure to insure the closing of the valve 14 at certain times when this is ldesirable.

In the normal operation of theJ system with the valves 4 open, steam is being admitted into the radiators, and in passing outwardly toward the discharge pipe, pressure is exerted against the underside of ydiaphragm 9 thus raisinsr valve 14 from its seat a short distance 'whereupon the steam rushes between lthe valve and seat and through the restricted Dort 15 into the outlet 3. Such How causes a void 'v' at the lower end of the passageway 16 and automatically removes pressure from the passageway 16 and chamber 11. In other words, a suction ei'ect is caused below the passageway 16 which is communicated to the upper diaphragm chamber 11 and assists in holding the valve raised. The weight of the valve is always acting on the steam flowing between it and the seat and causes maintenance of the void lv.

Should one of the valves 4 be suddenly closed, a rapid condensation of, the steam within the radiator will result and cause a partial vacuum to form and in turn produce a pressure of less degree in the radiator than in the return pipe '3 which would naturally cause the discharge steam to return to the radiator causing the undesirable re-heating. Bv reason of the provision of the bleeder passage 16 in the stem of valve 14, steam will collect in the chamber 11 and exert a great pressure over the large area of the diaphragm in chamber 11 thus causing valve 14 to be re-seated, this being accomplished vquickly because of the difference in pressure in the radiator and the return ordischarge pipe.

Thus, the higherthe pressure in the discharge pipe 3 and the lower the pressure in the radiator 2, the more pressure will be brought to bear against the diaphragm 9 and consequently the valve seat 15 thus insuring an absolute seal against the return of the steam into the radiator from the discharge pipe line.

In a check valve for preventing the back heating of a steam radiator, 'the combination of a casing having a valve chamberfand an inlet and an outlet for said chamber, there being a restricted valve port between said inlet and outlet, a valve seat surrounding said port, the upper end of said casing being expanded, a diaphragm extending transversely across said expanded upper part to divide such part into an upper diaphragm chamber and a lower diaphragm chamber, said lower diaphragm chamber being at all times in communication with said Valve chamber, a valve suspended from said diaphragm and free to move downwardly with the diaphragm to engage said valvey seat to close said port, said diaphragm being entirely free to be raised to unseat the valve when the pressure at said inlet is greater than that at the outlet, said valve having a restricted passageway extending lengthwise therethrough for connecting said outlet with the upper diaphragm chamber when the valve isdown and in4 closed position, lsaid valve chamber being disconnected from the upper diaphragm chamber when the valve is closed. said valve being held closed by the pressure in the upper diaphragm chamber when the pressureat said outlet is greater' than at said inlet.

WILFRED SHURTLEFF. Witnesses:

L. C. BECKWITH, El C. JAMisoN. 

